Characterization of the inspiratory manoeuvre when asthmatics inhale through a Turbohaler pre- and post-counselling in a community pharmacy

Abstract

Dose emission from a Turbohaler® has been shown to be dependent on the rate of inhalation, with an optimal flow of 60 l min-1 recommended. Some patients may need counselling to achieve this fast inhalation. Inhalation rate profiles of 24 asthmatics were measured when they inhaled through a placebo Turbohaler®. The setting was a community pharmacy when the asthmatics came to collect their next supply of medication. Profiles were measured before and after counselling on how to use the Turbohaler. The mean (SD) peak inhalation rate through the Turbohaler pre- and post-counselling was 48.0 (16.8) and 54.7 (17.6) l min-1, and their inspiratory volume was 1.75 (0.68) and 1.94 (0.62) l, respectively. Their mean (SD) percent predicted FEV1 was 57.0 (18.9)%. After counselling, 12 patients achieved an inhalation rate of > 60 l min-1 and a further four obtained > 55 l min-1. Emphasis should be placed on counselling patients prescribed all types of inhaled devices rather than concentrating on metered dose inhalers. © 2000 HARCOURT PUBLISHERS LTD.